1. Field of the Invention
The present invention relates to a game apparatus and a game method for displaying a moving body on a game screen, and a computer-readable storage medium storing a program for causing a computer to act as such game apparatus.
2. Related Background Art
It is common practice to present virtual three-dimensional display by polygons in the field of recent games, particularly, in the field of race games. To improve the quality of the game screen, the games with such virtual three-dimensional display by polygons usually employ a technique of pasting an image preliminarily prepared for the polygons (i.e. texture mapping), on a model (an assembly of many polygons), such as a car manipulated by a player.
In connection with the above technology, Japanese Patent Application Laid-Open No. Hei 8-63616 describes a technique for providing the game screen with realism by storing a plurality of textures for one display object and appropriately switching between the textures according to circumstances of the display object. Use of this technique can provide the image comprised of polygons with dynamic change, but, for further addition of dynamic presentation, more texture images must be stored for each polygon. However, when this technique of switching between the texture images was used for expressing reflective light of a road lamp which is reflected on a car in the race games, it is difficult to express continuous change of a number of texture images required for each polygon.
An object of the present invention is to provide a game apparatus, a game method, and a computer-readable storage medium capable of expressing the continuous change of the image on the polygons particularly, the continuous change of reflective light reflected on the display object or the like.
One aspect of the present invention provides a game apparatus for displaying a game image having a moving body moving in a virtual space, the game apparatus comprising, a polygon data memory for storing polygon data which define shapes of polygons constituting the moving body, a texture image memory for storing a texture image which indicates a reflected state of ambient light, a position specifying unit for specifying a position of the moving body in the virtual space, and a first image drawing unit for drawing a polygon based on the position of the moving body and the polygon data, a determination unit for determining a part of the texture image stored in the texture image memory based on the specified position of the moving body, and a second image drawing unit for drawing a translucent polygon over the polygon of the moving body, the translucent polygon having pasted thereon the part of the texture determined by the determination unit.
The game apparatus of this structure may display a pattern of ambient light moving according to movement of the moving body in the virtual space, on the surface of the moving body, whereby display screens provide increased realism.
In realizing the game apparatus of the present invention, polygon data memory may store the polygon data to define the shapes of the polygons by coordinates of respective vertices and normal vectors at the respective vertices.
The invention also provides a game apparatus in which reflection of curved part also appears with increased realism.
In realizing the game apparatus of the present invention, the texture image memory may store a texture image in which a plurality of pixels are equal to each other at places spaced by a first predetermined distance in a first predetermined direction and in which a plurality of pixels are equal to each other at places spaced by a second predetermined distance in a second predetermined direction, and the game apparatus may further comprises computing unit for calculating reference coordinates, based on the position specified position, utilizing a procedure of yielding identical results at regular intervals in each change of the position along the first predetermined direction by the first predetermined distance and each change of the position along the second predetermined direction by the second predetermined distance and additionally the second image drawing unit may determine the portion of the texture image pasted on the translucent polygon, based on the reference coordinates calculated by the computing unit.
A game apparatus according to another aspect of the present invention is a game apparatus for displaying a game image in which a moving body moves in a virtual space, wherein the moving body is displayed in a form in which a translucent image indicating a reflected state of ambient light is superimposed on a surface of the moving body and in which the reflected state of ambient light moves in accordance with movement of the moving body.
Another aspect of one invention is a game image display method for displaying a moving body moving in a virtual space. The game method comprises specifying a position of the moving body in the virtual space, and drawing a polygon based on the specified position of the moving body and polygon data defining shapes of a plurality of polygons constructing the moving body, and drawing, over a predetermined polygon of the moving body, a translucent polygon having the same shape as the predetermined polygon, wherein the translucent polygon includes a texture image indicating a reflected state of ambient light pasted thereon according to the specified position.
Another aspect of the invention provides a computer readable recording medium containing a program for causing a computer to display a game image in which a moving body moves in a virtual space, wherein the program causes the computer to perform the process comprising specifying a position of the moving body in the virtual space, and drawing a polygon based on the specified position of the moving body and polygon data defining shapes of a plurality of polygons constructing the moving body, and drawing, over a predetermined polygon of the moving body, a translucent polygon having the same shape as the predetermined polygon, wherein the translucent polygon includes a texture image indicating a reflected state of ambient light pasted thereon according to the specified position.
The computer-readable storage medium of the invention causes a computer to act as the game apparatus of the present invention described above.
Another aspect of the invention provides a computer data signal embodied in a transmission medium, the computer data signal containing a game program for displaying a game image in which a moving body moves in a virtual space, wherein the game program causes a computer to perform a process comprising, specifying a position of the moving body in the virtual space, and drawing a polygon based on the specified position of the moving body and polygon data defining shapes of a plurality of polygons constructing the moving body, and drawing, over a predetermined polygon of the moving body, a translucent polygon having the same shape as the predetermined polygon, wherein the translucent polygon includes a texture image indicating a reflected state of ambient light pasted thereon according to the specified position.
Another aspect of the invention provides a computer program product for displaying a game image in which a moving body moves in a virtual space, the computer program product comprising, computer code for specifying a position of the moving body in the virtual space, and computer code for drawing a polygon based on the specified position of the moving body and polygon data defining shapes of a plurality of polygons constructing the moving body, and computer code for drawing, over a predetermined polygon of the moving body, a translucent polygon having the same shape as the predetermined polygon, wherein the translucent polygon includes a texture image indicating a reflected state of ambient light pasted thereon according to the specified position.
The present invention will be more fully understood from the detailed description given hereinbelow and the accompanying drawings, which are given by way of illustration only and are not to be considered as limiting the present invention.
Further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will be apparent to those skilled in the art from this detailed description.